Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Platefire on October 07, 2023, 10:41:58 pm
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Looks like another no go to me! I'm ask to put a Princeton 6G2 without Trem circuit into this Voice of Music chassis. Considering adding a 12AX7 pre-amp tube,input jack, Speaker Jack, volume pot, Tone pot, IED power cord connection, fuse holder, power switch, fixed bias circuit---I don't believe I see any way to squeeze it all in. Plus the noise issues you may encounter with everything jammed up. I told the guy I would give it a look and get back to him. Pictures attached.
If you enjoy working out impossible puzzles, this might be the project for you:>)
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Pass.
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It is out of a tape/phono deck, isn't it? Not complete on its own even in the original VoM implementation? And that cap-can sticking out!!
Leave this part unmolested (it really is a fine music-amp as-is). Put it in a bigger box with a preamp, knobs, jacks, modern 120V inlet/fusing, etc.
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Oddly enough, I got one of those VOM phono amps on eBay not long ago, and looks like the same model. I was thinking I might be able to mod it into something fun, but then decided just to use the parts. I found that the power transformer was perfect for a 6G2, and so I got a Fender Sidekick Reverb 35 as a donor amp, and built the 6G2 complete with tremolo (something you really don't want to leave out because it really sounds great). I added a 3-way NFB switch and a Framus mid mod. It was a bit of a tight fit for the chassis, but it turned out great, plus the cabinet is made for a 12" speaker. I've got a late 60s Oxford 12T6 in there now, and it sounds really nice.
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dogburn---Good! I haven't thought much about a 6G2 until I got this request and have been researching about it. Apparently as you say the trem sounds awesome and the amp has it own unique sound that leans kinda sorta to a 5E3. At least that's what I read. Well tell me this, what chassis did you end up using to build your 6G2??
sluckey and PRR, you confirmed what I was already thinking, Thanks! It would need to be done like dogburn did with his
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Now you're talking. Get a larger chassis. Keep the tubes and the iron. Throw the rest away.
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I stripped out the innards from the Sidekick Reverb 35 and used that chassis. Worked quite well since that VOM power transformer is a stand-up model. Then after I had built it, I found the D-Lab guy on Youtube had done the same thing - Sidekick Reverb 35 into a 6G2. I suspect you could use other Fender Sidekick amps as well, as long as the dimensions are big enough to fit the components in.
(http://)
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A little bit more info, a different slant. He has a Fender Frontman 25R he wants to gut and use the VOM tubes & transformers. So I'm in the process of getting chassis dimensions.
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I used to have a Frontman 25, and that cabinet might work, though a bit of a tight fit for all the 6G2 components. I used a Hoffman eyelet board, but you could probably find one or design one to take up a bit less space.
By the way, using that VoM power transformer, the voltages were pretty much spot-on in reference to the Fender specs. And my amp is very quiet in terms of hum and hiss. But I did not use the VoM OT.
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Best I can tell, this is the shape of the chassis. Kind of strange, building on the slant. Guess that won't effect the flow the electrons:>)
This is a little more space but still don't set right with me--everything on the slant. Power transformer may be
conflicting with speaker space
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I thought maybe you'd be getting a separate chassis made, since that slanting chassis could be a problem with the transformers and tubes angled in toward the speaker. If I had the tools, I'd want to bend it and re-shape it to be straight rather than angled.
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I've done a couple of these re-fits... in both, I used an aluminum angle mounted to chassis back to create a solid horizontal mounting for the power tubes and cut away (or cut wide holes) in the chassis to allow them airflow. Also mounting the power transformer to back of the chassis also worked in one case, but required reinforcing to make the mount solid (in the other case I mounted the transformer in a sub chassis at bottom of cab). Both amps worked out pretty well, but the amount of jiggering needed to make everything fit takes time and planning. For me, worth doing once or twice, but I'll avoid repeating this approach if I can avoid it.
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Thanks for sharing your experiences with these chassis CascoSieg. With all the re-builds I've done re-shaping chassis to make things work, I'm kind of where your at of avoiding repeating approach. No use beating your brains out if you don't haft to. I think this has pretty much played itself out and is still at no go in my book. Thanks, Platefire